Fix container mount cleanup issues

- Refactor generic and path based cleanup functions into a single function.
- Include aufs and zfs mounts in the mounts cleanup.
- Containers that receive exit event on restore don't require manual cleanup.
- Make missing sandbox id message a warning because currently sandboxes are always cleared on startup. libnetwork#975
- Don't unmount volumes for containers that don't have base path. Shouldn't be needed after #21372

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

daemon/daemon_linux_test.go

@@ -59,7 +59,7 @@ func TestCleanupMounts(t *testing.T) {
 		return nil
 	}
 
-	d.cleanupMountsFromReader(strings.NewReader(mountsFixture), unmount)
+	d.cleanupMountsFromReaderByID(strings.NewReader(mountsFixture), "", unmount)
 
 	if unmounted != 1 {
 		t.Fatalf("Expected to unmount the shm (and the shm only)")
@@ -97,7 +97,7 @@ func TestNotCleanupMounts(t *testing.T) {
 		return nil
 	}
 	mountInfo := `234 232 0:59 / /dev/shm rw,nosuid,nodev,noexec,relatime - tmpfs shm rw,size=65536k`
-	d.cleanupMountsFromReader(strings.NewReader(mountInfo), unmount)
+	d.cleanupMountsFromReaderByID(strings.NewReader(mountInfo), "", unmount)
 	if unmounted {
 		t.Fatalf("Expected not to clean up /dev/shm")
 	}